The old Faroudja did do component to SVideo for the deinterlacing. This certainly included the 3000, 5000 (£20k!) and the 400 series. They got into much 'trouble' over this. I think the newer ones might be better but the chipsets they supply to others in panel based projectors / DVD PS players I am not sure about. Gordon might be in a better position to answer this, he gets to play with these expensive toys
An interesting question though.
I think the latest SIL 503 (Arcam / Iscan Pro), SIL504 (Tag) do not down convert to my knowledge.
Re all the lesser / other solution (Genesis etc) buyer beware again. Or at leastbuyer be educated.